JP2015105088A - Cooling device of vehicular controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling device of a vehicular controller, which cools a drive unit of an electric motor mounted to a vehicle and can improve the cooling performance.SOLUTION: A cooling device 10 includes: a radiator 20 radiating a heat quantity absorbed in an electric motor; a water pump 19 for circulating cooling water between the radiator 20 and a cooling flow passage 30; valves 28, 29 for switching the cooling flow passage 30; a boost cooling system 24; a front cooling system 25; and a rear cooling system 26. In the rear cooling system 26, the inside is separated into two cooling parts 27a, 27b. When the maximum rear wheel driving force is required, the valve 28 is switched to a bypass passage 37 side and the valve 29 is brought in an open state, so that the cooling water flowing out from a discharge port of the water pump 19 is circulated via the radiator 20, the boost cooling system 24, a bypass passage 37 and the first cooling part 27a of the rear cooling system 26 and flows into a suction port of the water pumps 19.

Description

  The present invention relates to a cooling device for a vehicle control device, and more particularly to a cooling device mounted on a vehicle including an electric motor that drives front and rear wheels.

  In recent years, hybrid vehicles, electric vehicles, and electric four-wheel drive vehicles that run with driving force from an electric motor have been attracting attention and put into practical use as environmentally friendly vehicles. A hybrid vehicle is a vehicle that uses a DC power source, an inverter, and an electric motor driven by the inverter as a power source in addition to a conventional engine. That is, a power source is obtained by driving the engine, a DC voltage from a DC power source is converted into an AC voltage by an inverter, and an electric motor is rotated by the converted AC voltage to obtain a further power source. is there.

  In such a vehicle, since a power control unit such as an inverter including a power element that drives an electric motor generates heat during operation, a cooling device is often provided to cool the power control unit. It has been proposed (see, for example, Patent Document 1). According to the technique described in Patent Document 1, in a hybrid vehicle, an inverter and a motor generator are arranged in series with respect to a cooling medium path (cooling flow path), and cooling water is always supplied by a water pump. When high cooling performance is required on the inverter side, the flow path through which the cooling water flows is switched by a switching valve to cool only the inverter.

JP 2009-40320 A

  For example, an electric four-wheel drive vehicle is an automobile equipped with an electric motor for driving a rear wheel having a relatively large output. Conventionally, in an electric four-wheel drive vehicle, the cooling capacity of a rear drive cooling system (hereinafter referred to as a rear cooling system) that cools a rear wheel drive unit (hereinafter referred to as a rear drive unit) is a front wheel drive unit (including a booster unit). Hereinafter, the cooling capacity of the boosting cooling system and the front driving cooling system (hereinafter referred to as front cooling system) for cooling the front driving unit is set low. For this reason, when it is necessary to increase the output of the rear drive unit such as when the vehicle is traveling on a hill, the heat generation of the rear drive unit increases, so the cooling capacity of the rear cooling system needs to be increased.

  However, if the cross-sectional area of the flow path of the heat sink of the rear cooling system is reduced to increase the cooling capacity and the flow velocity is increased, the pressure loss of the rear cooling system increases. When the pressure loss increases, the water pump cannot supply a sufficient flow rate with respect to the pressure loss, and the flow rate of the cooling water flowing through the entire cooling flow path decreases. For this reason, it becomes difficult to raise the cooling capacity of the rear cooling system to the same level as that of the front cooling system. As a result, the performance of the electric four-wheel drive vehicle cannot be improved.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a cooling device for a vehicle control device that can cool a drive unit of an electric motor mounted on a vehicle and improve cooling capacity. It is to provide.

  In order to solve the above-mentioned problem, the invention described in claim 1 is a cooling device for a vehicle control device, wherein a cooling flow path through which a cooling medium flows and at least two drive units mounted on the vehicle are cooled. First and second drive cooling systems that cool by a medium; a boost cooling system that boosts a DC power source that drives an electric motor and cools a boost unit that supplies a DC voltage to the drive unit by the cooling medium; and A pump for flowing the cooling medium in the cooling flow path; a radiator provided in series with the pump on the cooling flow path for circulating the cooling medium; and passing the cooling medium to dissipate heat; and A first and a second valve for switching states and changing the ability to cool the drive cooling system with the cooling medium; At least one of the drive cooling system, characterized by comprising a first and a second cooling portion formed in two stages can flow the cooling medium.

  According to the above configuration, since the two-stage cooling unit capable of circulating the cooling medium is provided in one of the drive cooling systems that cools at least two drive units that drive and control the electric motor, each cooling unit is provided according to the cooling request. The cooling capacity of the drive cooling system can be changed by changing the flow rate by the flow of the cooling medium flowing through or stopping. As a result, the cooling capacity of the drive cooling system can be improved by suppressing the pressure loss and increasing the flow velocity, and the output of the drive unit can be improved.

  According to a second aspect of the present invention, there is provided the cooling device for a vehicle control device according to the first aspect, wherein the one drive cooling system uses the second valve in response to a request to increase the cooling capacity. The gist is to circulate the cooling medium only to one of the cooling sections by switching the cooling flow path.

  According to the above configuration, it is possible to flow the cooling medium only to one of the two cooling units of the driving cooling system by switching the cooling flow path using a valve in response to a request for increasing the cooling capacity. The flow rate of the cooling medium flowing through the drive cooling system is increased. As a result, an increase in pressure loss can be suppressed and the cooling capacity of the drive cooling system can be improved without increasing the capacity of the pump.

  According to a third aspect of the present invention, in the cooling device for a vehicle control device according to the first or second aspect, the other driving cooling system is configured such that the cooling flow path is on the bypass passage side by the first valve. The gist is to stop the flow of the cooling medium by switching.

  According to the above configuration, when only one drive unit is driven by a motor, the cooling capacity of one drive cooling system is distributed at the maximum, the valve is switched to bypass the cooling flow path, and the other drive cooling system is distributed. Is stopped, and an increase in pressure loss can be suppressed. Thereby, even if it is the same pump capability, the cooling capability of a drive cooling system can be improved.

  ADVANTAGE OF THE INVENTION According to this invention, the cooling device of the control apparatus for vehicles which can cool the drive unit of the electric motor mounted in a vehicle and can improve cooling capacity can be provided.

1 is a block diagram showing a schematic configuration of an electric four-wheel drive vehicle equipped with a vehicle control device according to an embodiment of the present invention. The figure which shows the structure of the cooling passage of the cooling device of the control apparatus for vehicles. (A) is sectional drawing of the side surface which shows schematic structure of a rear cooling system, (b) is the front view which looked at the rear cooling system in Fig.3 (a) from the arrow A direction.

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.
FIG. 1 is a block diagram showing a schematic configuration of an electric four-wheel drive vehicle equipped with a vehicle control device 1 according to an embodiment of the present invention.

  As shown in FIG. 1, an electric four-wheel drive vehicle (electric 4WD) includes an engine 15, a motor generator 11, an electric motor for driving rear wheels (hereinafter referred to as a rear drive motor) 8, a battery 2, and these And a vehicle control device 1 that controls the driving of the vehicle. The battery 2 is a high voltage (for example, 250V) direct current power source, and is composed of, for example, a rechargeable battery such as chargeable / dischargeable nickel metal hydride or lithium ion. The battery 2 supplies DC power to the boost unit 18 and is charged by DC power from the boost unit 18.

  The driving force of the engine 15 and the motor generator 11 is transmitted to the front wheels 12 via a transmission (transmission) 16 to drive the front wheels 12. The output of the engine 15 is controlled by a command from an engine ECU (not shown) and not only drives the front wheels 12 but also drives the motor generator 11 in some cases. The motor generator 11 functions as a generator or functions as a motor according to the traveling state of the vehicle, and when the front wheels 12 are driven, the motor generator 11 is motor-driven using the electric power stored in the battery 2. . When regenerative braking is performed by the front wheels 12, regenerative power obtained by the motor generator 11 is supplied to the battery 2 and charged. When generating power, the motor generator 11 uses the power of the engine 15 to output AC power as a generator.

  The vehicle control device 1 mounted on the vehicle includes a booster unit 18, a front drive unit 22 as a motor control device (ECU) that controls the motor generator 11, and a motor control device (ECU) that controls the rear drive motor 8. ) As a rear drive unit 23. The front wheel (front) side inverter 13 is provided for arbitrarily controlling required power in the motor generator 11 based on a command from the front side control circuit (signal processing circuit) 14. Then, the DC power stored in the battery 2 is converted into AC power and supplied to the motor generator 11. At the time of regenerative braking or power generation, AC power is converted into DC power by the inverter 13 and supplied to the battery 2 via the boost unit 18.

  The DC voltage of the battery 2 is boosted to a high voltage (for example, 600 V) by the boosting unit 18 and the boosted DC voltage is supplied to the front-side inverter 13 and a rear-side inverter 3 described later. A relay (not shown) is provided between the booster unit 18 and the battery 2, and the high voltage is cut off when the vehicle is not in operation. The inverter 13 drives and controls the motor generator 11 when the engine is started. After the engine is started, the AC power generated by the motor generator 11 is converted into direct current by the inverter 13 and is converted to a voltage suitable for charging the battery 2 by the boost unit 18. The battery 2 is charged after conversion.

  The rear drive unit 23 includes a rear wheel (rear) side control circuit 6 and a rear side inverter 3, and is connected to the rear wheel drive device 9. The control circuit 6 is connected to an auxiliary power source (not shown) having a low voltage (for example, 12V) and receives a command from the vehicle control unit 17 that controls driving of the vehicle, and controls the rear wheel driving device 9 and the like.

  In addition, an inverter 3 is provided based on a command from the control circuit 6 so that required power can be arbitrarily controlled in the rear drive motor 8, and the DC power stored in the battery 2 is converted into AC power to It is supplied to the drive motor 8. When the vehicle is braked, the rear drive motor 8 is regenerated by the regenerative torque from the rear wheel 7, and regenerative power can be obtained.

  The rear wheel drive device 9 includes a rear drive motor 8, a reduction gear (differential gear) 4, and a clutch 5, and the clutch 5 is installed at the final stage of the reduction gear 4. As the rear drive motor 8 for the drive source, for example, a three-phase brushless motor is used. The rear drive motor 8 is a permanent magnet such as an IPM motor including an embedded magnet type rotor in which a permanent magnet is embedded and fixed in a rotor core, or an SPM motor including a surface magnet type rotor in which a permanent magnet is fixed to the surface of the rotor core. A synchronous motor is used.

  The driving force of the rear drive motor 8 is transmitted to the rear wheel 7 via the speed reducer 4 and the clutch 5, respectively, and drives the rear wheel 7. When the clutch 5 is connected, the rear wheel 7 is driven by the rotational force of the rear drive motor 8. When the clutch 5 is released, the rear drive motor 8 is mechanically disconnected from the rear wheel 7, and the rear wheel 7 does not transmit driving force to the road surface.

  Further, the vehicle control unit 17 is connected to the engine ECU, the control circuit (front) 14, the control circuit (rear) 6 and communication means such as CAN, and the front wheel motor generator 11 and the rear wheel rear drive motor 8. This is a controller that controls the entire drive system, such as calculating the command value. Based on the engine speed and torque command obtained from the vehicle control unit 17, the control circuit 14 controls the motor generator 11 and the inverter 13, and the control circuit 6 controls the rear drive motor 8 and the inverter 3.

  Next, FIG. 2 is a diagram showing the configuration of the cooling passage of the cooling device 10 of the vehicle control device 1. It should be noted that the objects to be cooled are the booster unit 21, the front drive unit 22, and the rear drive unit 23 that are included in the vehicle control device 1 shown in FIG. 1, and in the following, the cooling medium is liquid (cooling water). Will be described.

  Conventionally, since the electric four-wheel drive vehicle of the present embodiment travels mainly by front drive, the cooling capacity of the rear drive unit 23 is suppressed to be lower than that of the front drive unit 22. Further, the pressure loss of the entire cooling device 10 including the cooling flow path 30 includes the radiator 20, the boost cooling system 24, the front cooling system (first driving cooling system) 25, and the rear cooling system (second driving) shown in FIG. (Cooling system) 26 and the total pressure loss of the piping of the cooling flow path 30. The water pump 19 is provided so as to ensure a sufficient flow rate of cooling water for this total pressure loss.

  As shown in FIG. 2, the cooling device 10 includes a radiator 20 that dissipates heat absorbed by the motor generator 11 and the rear drive motor 8 with reference to FIG. 1, and cooling water between the radiator 20 and the cooling flow path 30. A water pump 19 for circulating the air, valves 28 and 29 for switching the cooling flow path 30, a boost cooling system 24, a front cooling system 25, and a rear cooling system 26. Each of the cooling systems 24, 25, and 26 is a heat sink in which cooling fins are formed, and the heat generating portions of the units 21, 22, and 23 are in contact with the heat sinks. The rear cooling system 26 is divided into two cooling parts (first and second cooling parts) 27a and 27b, and an inflow port and an outflow port are provided separately.

  The radiator 20 and the water pump 19 are connected by a water pump discharge port side passage, and the water pump 19 and the cooling system side are connected by a water pump suction port side passage. The radiator outlet side of the cooling flow path 30 is connected to the boost cooling system inlet side, and the outlet side passage of the boost cooling system 24 is branched by the valve 28 into a front cooling system inlet side path and a bypass path 37. The front cooling system outlet side passage is branched and connected to the first cooling portion 27 a and the bypass passage 37 of the rear cooling system 26. The bypass passage 37 is connected to the second cooling unit 27 b of the rear cooling system 26 via the valve 29. The valves 28 and 29 can be controlled to be opened / closed and switched by the vehicle control unit 17.

  Here, in the electric four-wheel drive vehicle, when the maximum rear wheel driving force is required, the front side is driven by the engine 15, and the rear side is driven by the rear drive motor 8. The flow of the cooling water at this time is indicated by a solid arrow in FIG. The valve 28 is switched to the bypass passage 37 side to bypass the front cooling system 25, and the valve 29 is opened so that the cooling water does not flow to one second cooling part 27 b of the rear cooling system 26. Then, the cooling water flowing from the discharge port of the water pump 19 is sucked into the water pump 19 via the radiator 20, the boost cooling system 24, the bypass passage 37, and the other first cooling part 27 a of the rear cooling system 26. Circulates through the mouth.

  That is, normally, by flowing cooling water through both the cooling parts 27a and 27b, pressure loss can be reduced, the load of the water pump 19 can be reduced and the power consumption can be reduced, and only the first cooling part 27a is cooled. When water is allowed to flow, the flow rate in the rear cooling system 26 is increased, and a large cooling capacity can be obtained. Further, by increasing the pressure loss due to the rear cooling system 26 by bypassing the front cooling system 25 having the largest loss, the increase in pressure loss can be suppressed. Accordingly, the flow resistance of the entire cooling device 10 including the cooling flow path 30 can be reduced, and the total pressure loss can be suppressed to be equal to or lower than the pressure loss in the state before the cooling water flow is changed. There is no need to strengthen 19 abilities.

  Next, FIG. 3A is a side sectional view showing a schematic configuration of the rear cooling system 26, and FIG. 3B is a front view of the rear cooling system 26 in FIG. .

  As shown in FIG. 3A, the cooling water 35 that has flowed in (indicated by the solid arrow line) from the inflow port 31a passes through the first cooling unit 27a (indicated by the broken arrow line) and flows out from the outflow port 32a (indicated by the solid arrow line). The cooling water 36 flowing in (indicated by a solid arrow) from the inflow port 31b passes through the second cooling part 27b (indicated by a broken arrow) and flows out (indicated by a solid arrow) from the outflow port 32b.

  Further, as shown in FIG. 3B, a plurality of fins 33 arranged in the direction of the flow of the cooling water and extending in the vertical direction are formed, and the long holes (gap) provided in the partition wall portion 34 are inserted. The space is divided into two cooling parts 27a and 27b. Cooling water 35 and 36 circulate in both cooling parts 27a and 27b, respectively. When the valve 29 (see FIG. 2) provided on the inlet side of the second cooling unit 27b is opened, the cooling water 36 does not flow to the second cooling unit 27b.

  As described above, the flow of the cooling water in the cooling flow path 30 is changed according to the load of the rear drive unit 23 with reference to FIG. At this time, it is possible to reduce the power consumption by reducing the load of the water pump 19 by flowing the cooling water only to the portion that needs to be cooled (the first cooling portion 27a).

  Next, the operation and effect of the cooling device 10 of the vehicle control device 1 according to the embodiment of the present invention configured as described above will be described.

  According to the above-described embodiment, the two front cooling systems 25 and the rear cooling system 26 that respectively cool the two front drive units 22 and the rear drive unit 23 that drive and control the electric motors (the motor generator 11 and the rear drive motor 8). One of the rear cooling systems 26 is provided with two-stage cooling units 27a and 27b through which cooling water (cooling medium) can be individually circulated. The cooling capacity of the rear cooling system 26 can be changed by changing the flow velocity by flowing or stopping the cooling water flowing through the sections 27a and 27b.

  Further, since the cooling flow path 30 can be switched by the valve 29 in response to the cooling request and the cooling water can flow only to the first cooling part 27a, the flow velocity flowing in the rear cooling system 26 increases. The cooling capacity of the rear cooling system 26 is improved. When only one rear drive unit 23 is driven by a motor while the other front drive unit 22 is driven by an engine while the vehicle is traveling, the cooling capacity of one rear cooling system 26 is circulated at the maximum, and the other front cooling system 25 is distributed. Can be stopped, so that the output of one rear drive unit 23 can be maximized.

  As a result, the cooling capacity of the rear cooling system 26 can be improved by increasing the flow velocity of the cooling water flowing in the rear cooling system 26, and the output of the rear drive unit 23 can be improved. Further, without increasing the capacity of the water pump 19, an increase in pressure loss can be suppressed and the cooling capacity of the rear drive unit 23 can be improved. Furthermore, the pressure loss of the front cooling system 25 can be reduced by bypassing the cooling passage 30 to the bypass passage 37. As a result, the cooling capacity of the rear cooling system 26 can be improved even with the same capacity of the water pump 19, and the fuel efficiency of the vehicle can be improved.

  As described above, according to the embodiment of the present invention, it is possible to provide a cooling device for a vehicle control device capable of cooling a drive unit of an electric motor mounted on a vehicle and improving the cooling capacity.

  As mentioned above, although embodiment which concerns on this invention was described, this invention can also be implemented with another form.

  In the said embodiment, although the example which used the liquid (cooling water) as a cooling medium was shown, it is not limited to this, Gas may be sufficient.

  Although the example using the valve 28 for switching the cooling flow path 30 and the valve 29 for opening and closing is shown in the above embodiment, the present invention is not limited to this, and a plurality of check valves may be used.

  In the above-described embodiment, the example in which the front cooling system 25 is bypassed by the bypass passage 37 and the cooling water is allowed to flow only to the first cooling unit 27a of the rear cooling system 26 has been described. It is also possible to reduce the power consumption of the water pump 19 when the engine is driven by flowing cooling water through both the cooling units 27a and 27b of the cooling system 26.

  In the above-described embodiment, the vehicle is described as an electric four-wheel drive vehicle. However, the present invention is not limited to this, and the vehicle control apparatus 1 using a three-phase alternating current as a drive source includes, for example, an engine 15 and an engine. It may be a parallel type hybrid vehicle including a front wheel drive motor generator 11 directly connected to 15 crankshafts, or may be applied to a series type hybrid vehicle or a series / parallel type hybrid vehicle using both. .

  Moreover, in the said embodiment, it can apply also to the electric vehicle which uses only the rear drive motor 8 as a drive source. As an electric vehicle, the rear drive motor 8 may be provided on the vehicle body side, or the rear drive motor 8 may be provided on the wheel side. Further, the vehicle may be a front wheel drive vehicle or a rear wheel drive vehicle. Alternatively, a vehicle in which the front wheels 12 are driven by the engine 15 and the rear wheels 7 are driven by the rear drive motor 8 may be used.

  In the said embodiment, although the cooling device 10 which cools the inverters 3 and 13 which drive the rear drive motor 8, and the pressure | voltage rise unit 21 was applied to the vehicle control apparatus 1, it was not limited to this, For example, it may be used for the inverter 3 such as an electric power steering device or an electric brake device, or other in-vehicle power conversion device. Moreover, you may apply to the electrical equipment apparatus of the other use provided with the electric motor with which high reliability and low cost are calculated | required.

1: vehicle control device, 2: battery (DC power supply), 3: inverter (rear),
4: Reduction gear (differential gear), 5: Clutch, 6: Control circuit (rear),
7: rear wheel, 8: rear drive motor, 9: rear wheel drive device, 10: cooling device,
11: Motor generator, 12: Front wheel, 13: Inverter (front),
14: Control circuit (front), 15: Engine, 16: Transmission (transmission), 17: Vehicle control unit, 18: Boosting unit, 19: Water pump,
20: Radiator, 21: Boosting unit, 22: Front drive unit (ECU),
23: Rear drive unit (ECU), 24: Boosting cooling system,
25: Front cooling system (first drive cooling system),
26: rear cooling system (second drive cooling system), 27a, 27b: first and second cooling units, 28, 29: first and second switching valves, 30: cooling flow path, 31a, 31b: inlet,
32a, 32b: outlet, 33: fin, 34: partition wall,
35, 36: Cooling water (cooling medium), 37: Bypass passage

Claims (3)

A cooling flow path through which the cooling medium flows;
First and second drive cooling systems for cooling at least two drive units mounted on a vehicle with the cooling medium;
A boost cooling system that boosts a DC power source that drives an electric motor and cools the boost unit that supplies a DC voltage to the drive unit with the cooling medium;
A pump for flowing the cooling medium in the cooling flow path;
A radiator that is provided in series with the pump on the cooling flow path for circulating the cooling medium, and that dissipates heat by passing the cooling medium;
First and second valves for switching the state of the cooling flow path and changing the ability to cool the drive cooling system with the cooling medium,
At least one of the drive cooling systems includes a first cooling unit and a second cooling unit formed in two stages through which the cooling medium can flow. The cooling device for a vehicle control device according to claim 1,
The one drive cooling system causes the cooling medium to flow only to one of the cooling units by switching the cooling flow path by opening the second valve in response to a request for increasing the cooling capacity. A cooling device for a vehicle control device. In the cooling device of the control device for vehicles according to claim 1 or 2,
The other drive cooling system stops the flow of the cooling medium by switching the cooling flow path to the bypass passage side with the first valve, and is a cooling device for a vehicle control device.

Images